Improvement in air-distributing pipes for furnaces



l. CBEIGH.

Air-Distributing Pipes for Furnaces..

Patented May 5,1874.

in said pipe.

UNITED STATES PATENT ALFRED J. GREIGH, OF MANSFIELD, OHIO.

Specification forming part of Letters Patent No. 150,401, dated May 5,1874; application filed March 17, 1874.

To all whom it may concern Be it known that I, ALFRED J. GREIGH, ofMansfield, in the county of Bichland, in the State of Ohio, haveinvented an Improvement in AinDistributing Pipes for Furnaces; and

1 do hereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the annexed drawings makinga part of this specification, in which like letters of reference referto like'parts, and in which.

Figure 1 represents afront elevation of furnace and pipe; Fig. 2, a sidesectional elevation of the furnace, grate, and cross-section of thepipe, along dotted line a a a a, Fig. 3; Fig. 3, a superficial or topview of the pipe with grate broken away to give a clear view.

The object of this invention is to equalize the currents of air throughthe collective orifiees in the distributing tube or pipe, so as toobtain an equal pressure at any point along said pipe, whether the samemay run under one or more furnaces or steamgenerators; and also that theescaping blasts shall be under the control of the operator, by thesimple manipulation of an orificed cover slide, with oblique openingscorresponding with the similar openings for air in a tapering pipe. ThisI do by employinga tapering pipe, whose diminishing caliber compensatesfor the progressive decrease of the advancing air-current-4n otherwords, where this pipe receives the blast it is largest, and itdiminishes in proportion to the successive outlets in its upper surface,so as to supply an equal blast or jet of air at each orifice. Theselatter are cut obliquely in that side of the pipe facing the grate aboveat suitable distances, the superior surface of the pipe being at thesame time parallel with the line of the grate-bars. The pipe is coveredabove by a sliding plate,which conforms to the upper surface, and ispierced with orifices exactly corresponding with those It slidessecurely in guides, and is moved by a lever or similar device inregulating the currents of air from the pipe.

I will now describe one of theforms in which- I make this apparatus.

In the drawings, A represents the grate; B, the ash-pit; O, the air tubeor pipe tapering from that end which receives the blast from a fan orpressure-blower, and pierced with several orifices, e e, &c., foremission of air, running obliquely across its upper surface. It maybemade of stout sheet-iron. At the end of the blast, or smaller end ofsaid pipe, an ash or dust trap, f, is provided, which slides in cleats,so that dust may be got rid of, which might enter the orifices e. Drepresents a sliding cover, fitting snugly to the upper surface of thepipe 0, and pierced with corresponding holes 0 e, &c. It slides incleats d d, and is moved back or forth by a lever, g, on the outside ofthe furnace. E, steam-generators.

. The operation of this invention is as fol lows: The pipe 0 is inflatedby a pressureblower, a fullopening of the slide D'giving a full blastupon the fire to supply oxygen and to cool the grate, saving by thismeans from one-sixth to one-fifth of the fuel. The pipe, by means of itstapering form, whether delivering a half or three-fourths blast, hasstill a large reserve of air, fully sufficient to prevent the burning ofthe pipe by heat, as no cut-off of the main current in the pipe is usedbetween the pipe and the blower, this being done by the sliding cover.

I am aware that air-distributing pipes and sliding attachments ascut-offs have previously been used in furnaces; but I claim the peculiarform of the pipe 0 and arrangement of holes thereon, together with theorifices in the cover.

The advantages of the tapering pipe (1 and slide are, that it secures anequal pressure or equal jets of air for its entire length, whereas inthe common forms of pipes for this purpose, and the mode of cutting off,or damping the blast at the furnaee-jamb or outside of the ash-pit, hasthe effect, where part of the blast is cut off, to blow very stronglyupon that part of the grate farthest from the cut-off, and much fainterfrom the intermediate orifices, or diminishing gradually toward thecut-off when situated on outside of the jamb I).

My invention does away with tall-chimneys, as the natural draft issuperseded by an artificial one, which is consumed directly in the fire,without creating extra draft in the chim ney.

Vhat I claim as my invention is- A tapering tube, (3, with obliqueorifices e, provement in blast-pipes for furnaces, I have in combinationwith a sliding cut-off, D, havhereunto set my hand this 11th day ofMarch, ing orifices corresponding with those in the 1874.

tube, and arranged to Work in guides d, by ALFRED J. OREIGH. means of alever, g, substantially as and for Vitnesses: the purpose set forth. H.W. ELLS,

In testimony that I claim the foregoing i1n- JAMES M. MORSE.

